Subthreshold mental disorders can reduce one's pleasure in life, even if the dysfunction is not major. A subthreshold mental syndrome comprises a subset of the symptoms of a recognized mental disorder. Even if the symptoms do not match those of a recognized disorder, a shadow disorder may be diagnosed if the patient is clearly distressed.
Dysfunctions associated with subthreshold mental illness include poor performance at school, inability to keep a job, friends or a spouse, and inappropriate social behaviour.
Subclinical dysfunction in parents may be associated with clinical dysfunction in their children.